Grinding and drainage means for waste disposal apparatus



July 31, 1951 J H POWERS 2,562,736

GRINDING AND'DRAINAGE MEANS FOR WASTE DISPOSAL APPARATUS I Filed Dec. 1, 1948 2 Sheets-Sheet 1 1T1 venbor James H."F?ower His Attorney.

July 31, 1951 J. H. POWERS 2,562,736

GRINDING AND DRAINAGE MEANS FOR WASTE DISPOSAL APPARATUS 2 Sheets-Sheet 2 Filed Dec.

Inventor; Jam es H. Ppwers,

H is Attorney.

Patented July 31, 1951 GRINDING AND DRAINAGE MEANS FOR WASTE DISPOSAL APPARATUS James H. Powers, Westport, Conn., assignor to General Electric Company, a corporation of New York Application December 1, 1948, Serial No. 62,946

2 Claims. I

This invention relates to waste disposal devices of the type in which kitchen waste and the like is commlnuted and flushed into a sewage system.

The comminuting or grinding means of these waste disposal devices include a garbage-receiving chamber having at or adjacent its bottom a rotatable disk provided with blade-like impeller members. Through suitable means a drive motor for the disk is started when water is caused to flow into or through the chamber, and largely by means of the impeller blades the pieces of garbage are thrown centrifugally against shredding devices or cutters fixed to the wall of the grinding chamber, and are ground or comminuted thereby. The mixture of finely ground garbage and water then passes through strainer openings in the wall 7 of the chamber, to the waste line. Waste disposal devices of this type must handle all kinds of garbage and like kitchen waste, from long, hard bones to soft, fibrous materials such as peapods and the like. In contemporary constructions the impellers and shredder elements have been so arranged that the impellers pass in front of the shredders in relatively close proximity thereto so as to shear or chop the softer waste materials; but

such constructions have not been entirely satisfactory with bones and other hard objects which may become confined between the impeller and the shredder element, with danger of jamming the mechanism, or held by the impellers and carried about the chamber without being ground.

It is, therefore, a principal object of the present invention to provide an improved grinding mechanism for garbage disposal apparatus which will handle all types of garbage with equal effectiveness. It is another object of the invention to provide a grinding apparatus as aforesaid in which the impeller blades are relatively low and pass beneath the cutter elements, said blades being adapted not only to cut or shred soft material coming into contact therewith but to tumble long bones or other hard materials so that as these latter materials are struck, they are cut or gouged and then thrown upwardly. to be struck and similarly treated by the succeeding impeller.

It is still a further object of the invention to provide drainage ports through the lower wall of the grinding chamber, said drainage ports cooperating with the impellers to provide additiona1 comminution means.

It is yet another object of the invention to provide an improved impeller blade for garbage disposal apparatus.

In the accompanying drawings, Fig. 1 is a side elevation, partly in section, showing a garbage disposal apparatus embodying the present invention; Fig. 2 is a plan sectional view looking in the direction of lines 2-2 of Fig. 1; Fig. 3 is an exploded perspective of the comminution elements with only a portion of the shredder wall being shown; Fig. 4 is an end view of one of the impeller blades; and Fig. 5 is a fragmentary perspective of a second form of shredder wall.

A. garbage disposal unit embodying the present invention comprises an upper casing portion Iil adapted for securement by suitable adapter rings H to the drainage opening of a kitchen sink or the like l2. A motor housing I 3 afixed to the bottom portion of the casing contains a motor [4 with its shaft I5 supported in suitable bearings, as shown, for rotation in a vertical plane. An absorbent mass I6 and wicks I! comprise elements of a lubrication system. The motor frame wall l8 within which the motor shaft and bearings are supported is shaped to provide an annular drainage chamber !9 which receives the comminuted waste and water for discharge through a drainage fitting lea which is connected with the usual trap (not shown) of a sewage system.

The casing I0 defines a main chamber 20 of substantial volume. Said chamber is desirably frusto-conical flaring somewhat more sharply at its lower portion to define a circular shredding chamber 2!. The lower wall portion 22 of the shredding chamber is the area of greatest abrasive contact during operation, and it is advantageous to form said wall separately from hard, wear-resisting material; the remainder of the chamber may accordingly be made of a less expensive, pref erably lighter weight, material. Gaskets 23 and 25 of rubber or other resilient material are interposed between the wall 22 and the respective upper and lower casing parts, to seal against leaka e and absorb vibrations incident to use. Projecting inwardly from the wall 22 so as to terminate well above the lower edge thereof are a suitable plurality of shredder elements 25. Three equidistantly spaced elements produce satisfactory results. These shredder elements cooperate with the impeller in comminuting the waste material, as presently described, and are subjected to severe vibrations and impact of the materials being operated upon. Hence, it is preferable to make the shredders integral with wall 22. The outer surface of the shredders 25 is grooved, as clearly appears in Fig. 3, to provide two or more preferably parallel and horizontal cutting edges 26.

Suitably supported on the end of shaft l5, as by threaded connection therewith, is a flywheel Z1.

Sealing means 30 guard against the introduction of waste matter into the shaft bearings. The flywheel has diametrically opposed pairs of ribs 3i and 32 which provided drainage passages 33 communicating with the drainage chamber I9, as shown in Fig. 1. The relatively wide slots 34 snugly receive the depending ears 35 of a shoe 36 which rests upon and is supported by the respective ribs 3!, 32. The shoe may be screwed to the flywheel, as indicated. As is apparent from Fig. 1, the shoe 35 forms the floor of the shredder chamber. The shoe is provided with groups of drainage openings 31 which are positioned above the respective drainage passages 33, and are radially inward of the shredder wall 22.

The pairs of cars 35 are at diametrically opposite locations on the shoe 36 and form mounting means for impeller blades 38, said blades being pivotally supported by said ears 35 and a suitable pin or bearing 40. The side walls of the respective slots 34 confine the pivot pins against sideward movement. The impeller blades 38 are of a hard wear-resistant material and in a presently preferred form, are shaped to provide spaced teeth H, 42 between which is the arcuate edge portion 43. The upper wall of the impeller blades preferably slopes rearwardly, as indicated in Fig. 4, to give an incisive edge portion which will effectively gouge or tear the material within the shredder chamber as the flywheel rotates. It will be noted from Fig. 3 that, when in the operative position, said position being the result of centrifugal forces developed by the rapid rotation of the flywheel, the tooth edges of the impeller blades are at a relatively low elevation with respect to the shoe 36; and the upwardly sloping wall 44 about the impeller blades is so arranged relative to the height of the cutting edges of the respective blades that material resting upon the shoe 36 is deflected by said wall 44 substantially directly into forceful contact with the cutting edge of the impeller blades and the teeth thereof. Hard materials, such as pieces of bone, rise upwardly and over the relatively low impeller blades, to be out and tumbled thereby and dropped into the path of the teeth of the next succeeding impeller element. The sloping wall surfaces are also effective to move and distribute masses of material during the starting stage of flywheel operation so as to prevent accumulation of materials which might jam the blades and impose an abnormal strain on the drive motor. Material resting upon the center portion of the shoe is effectively distributed and set in motion by the edged abutments 45 projecting upwardly from the central zone of the shoe.

The impeller blades 38 are freely rotatable with respect to the flywheel and are balanced so that when the flywheel is at rest the blade will rotate clockwise of Fig. 1 until its rear wall 46 rests against the end wall 4'! of the blade pocket. Under the influence of oentrifugffal force, the blade will rotate in the opposite direction until it comes into operative position, determined by the engagement of shoulder 48 with the underside of the flywheel shoe, in which the forward edge 49 of blade 38 is in close relationship with the lower portion of wall 22, and the top of tooth 4| is beneath and in close relationship with the bottom wall of the shredder element 25. The clearances are such that soft materials, and particularly soft, stringy materials, are sheared between the front edge of the blade and the wall 22, or between the upper edge of tooth 4| and either the shredder element 25 or the sharp shoulder 50 provided in wall 22, as appears clearly in Fig. 1. Notwithstanding this close clearance, jamming is prevented by the freedom with which the impeller blades may rotate into reclined position. Hard, bulky materials are engaged, cut and tumbled by the impeller blades, as aforesaid. With the blades beneath the level of the shredder elements, it is practically impossible for a hard bone, or the like, to become jammed between a blade and a shredder. Such materials will be tumbled upwardly against the shredder or over the impeller, but will not jam against the shredder.

As is well known in the art, the devices are provided with switch means which start the motor only when the water flows into the chamber 20. Such switch controls, being well known and forming no part of the present invention, have not been illustrated. The mass of comminuted waste material and water within the shredder chamber is thrown outwardly against the wall 22. Said wall is provided with strainer grooves or ports 52 communicating with the drainage chamber I9. In the number and arrangement of the drainage ports, the present invention differs importantly from the prior art of which I am aware; instead of the usual forty or more strainer grooves closely spaced around the lower edge of wall 22, the present invention has but six, and each of them cooperates with the forward edge 49 of the impeller blades to provide additional shearing surfaces, particularly effective with regard to the softer, stringier materials, such as pea pods and the like.

In the embodiment of Figs. 2' and 3, the portion of the shredder chamber wall 22 below the shoulder 50 is formed as a series of short walls which extend outwardly in the direction of rotation of the impeller, from the trailing edge 53 of each strainer port 52 to the leading edge 54 of the next port. The walls may be outwardly spiralling arcs, for example. Each trailing edge 53 therefore projects forwardly beyond its associated leading edge into the shredder chamber and provides a cutting surface for cooperation with the cutting edge of the forward wall 49 of each impeller blade. In the embodiment of Fig. 5, the edge 53a of the respective strainer ports is determined by a projecting shoulder 55 formed integral with the shredder wall. Either of these constructions insures a positive cutting or grinding operation at the strainer grooves, and avoids the possibility of the waste material merely sliding across the face of the strainer grooves.

It will be seen therefore that the blades 38 act not only as impellers to throw the garbage against the shredder wall 22 but individually and in cooperation with the undersurfaces of the shredder elements 25 and the edges 53 or 53a of the drainage ports 52, as cutters for both hard and soft materials. The continuous movement of the waste within the shredder chamber, caused by the tumbling of the hard bones over the blades and the rebound or deflection of materials from the drainage openings increases the efficiency of the comminution operation by exposing constantly changing surfaces or edges of the waste materials to shearing or cutting action, and produces a thorough saturation of the waste with the water supplied to the unit during the grinding operation. The mixture of finely divided waste and water passes through the strainer grooves 52 into the chamber [9, whence it is driven by the positive pumping action of the projections 56 of the flywheel 21 into the outlet 19a and then to the plumbing system.

As will be evident from the foregoing description, certain aspects of the invention are not limited to the particular details of construction of the exemplary embodiments illustrated, and it is probable that various modifications and applications of the invention will suggest themselves to those skilled in the art. It is my intention, therefore, that the appended claims shall cover such modifications and other applications as do not depart from the true spirit and scope of the present invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a waste disposal device, a wall which defines a circular shredding chamber to receive a mixture of water and waste material to be comminuted, a rotatable flywheel which forms a floor for said chamber, passages in the lowermost portion of the wall for conveying a mixture of water and waste material from said shredder chamber to a lower drainage chamber, shredding members projecting radially into said chamber from said wall immediately above said passages and overlying said flywheel in spaced relation therewith, and one or more impeller blades pivotally mounted in said flywheel at the periphery thereof, each blade having a forward wall, considered in relation to the direction of rotation of said flywheel, which rises substantially vertically to a series of radially spaced cutting edges separated by a concave structure having a cutting edge, none of said cutting edges being above the lower edge of the shredding members and the radially outermost of said cutting edges sweeping beneath the bottom wall of the shredding members upon rotation of the flywheel.

2. In a waste disposal device, a wall which defines a circular shredding chamber to receive a mixture of water and waste material to be comminuted, a rotatable flywheel which forms a floor for said chamber, circumferentially spaced strainer passages in the lowermost portion of the Number Name Date 1,156,147 Karns Oct. 12, 1915 1,483,803 Hartburg Feb. 12, 1924 1,687,886 Philipp Oct. 16, 1928 2,156,075 Alexay Apr. 25, 1939 2,220,729 Powers Nov. 5, 1940 2,322,058 Powers June 15, 1943 2,428,420 Green Oct. 7, 1947 2,442,820 Jordan June 8,1948 2,469,205 Powers May 3, 1949 2,476,630 Schindler July 19, 1949 FOREIGN PATENTS Number Country Date 191,081 Great Britain Nov. 8. 1923,

wall for conveying a mixture of water and waste material from said shredder chamber floor to a lower drainage chamber, shredding members projecting radiall into said chamber from said wall immediately above said passages and overlying said flywheel in spaced relation therewith, and a plurality of impeller blades pivotally mounted in said flywheel at the periphery thereof to swing in planes radially of said flywheel, each blade having a forward wall, considered in relation to the direction of rotation of said flywheel, which rises substantially vertically to a series of radially spaced cutting edges, none of the cutting edges being above the lower edge of the shredding members, and the radially outermost of said cutting edges sweeping beneath the bottom wall of the shredding members and radially opposite said circumferentially spaced strainer passages upon rotation of the flywheel.

JAMES H. POWERS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

